Is this an issue with my power supply or my motherboard?

[Duranson]

So I just built a new PC in the cooler master nr200. I've been having issues with the fans not spinning, graphics card not lighting up, but the ram lights up. I concluded that it's either an issue with the power supply or the motherboard.

When I tried to do qflash with just the motherboard and power supply (this is how qflash is intended to be done on a gigabyte motherboard) the light for qflash never turned on, and my power supply (sf750) fan never came on. The only indication that the system had any power was the fact that my USB flash drive with the BIOS update on it had a little flashing red light that was blinking, so it had to be getting power.

 

I I know that I did everything right and I triple checked my 8 pin and 24pin connectors when I was doing qflash, but nothing worked. When my system was fully assembled, the only thing that would light up was the ram.

This makes me wonder if it's the motherboard or power supply that's having an issue. I would assume the motherboard because the usb stick was getting power, but I just wanted to check.